Buoyancy effects on the vapor condensation rate on a horizontal liquid surface

The results are presented of a numerical study of the effects of buoyancy on the direct condensation of saturated or nearly saturated vapor on a horizontal liquid surface in a cylindrical tank. The liquid motion beneath the liquid-vapor interface is induced by an axisymmetric laminar jet of subcooled liquid. Analysis and numerical results show that the dominant parameter which determines the influence of buoyancy on the condensation rate is the Richardson number. However, the effect of buoyancy on the condensation rate cannot be quantified in terms of the Richardson number alone. The critical value of the Richardson number below which the condensation rate is not significantly reduced depends on the Reynolds number as well as the Prandtl number

Vapor condensation on liquid surface due to laminar jet-induced mixing: The effects of system parameters

The effects of system parameters on the interface condensation rate in a laminar jet induced mixing tank are numerically studied. The physical system consists of a partially filled cylindrical tank with a slightly subcooled jet discharged from the center of the tank bottom toward the liquid-vapor interface which is at a saturation temperature corresponding to the constant tank pressure. Liquid is also withdrawn from the outer part of the tank bottom to maintain the constant liquid level. The jet velocity is selected to be low enough such that the free surface is approximately flat. The effect of vapor superheat is assumed to be negligible. Therefore, the interface condensation rate can be determined from the resulting temperature field in the liquid region alone. The nondimensional form of the steady state conservation equations are solved by a finite difference method for various system parameters including liquid height to tank diameter ratio, tank to jet diameter ratio, liquid inflow to outflow area ratio, and a heat leak parameter which characterizes the uniform wall heat flux. Detailed analyses based on the numerical solutions are performed and simplified equations are suggested for the prediction of condensation rate

Dakwah Dan Problema Kemiskinan

Krisis ekonomi global berdampak tidak kunjung USAi, berimbas ke Indonesia tentu membuat bertambahnya jumlah masyarakat miskin. Data Pusat Statistik menunjukkan bahwa pada Maret 2013, jumlah penduduk miskin di Indonesia sebanyak 37,17 juta orang [16,58]. Jumlah ini dipastikan bertambah karena data statistik juga menunjukkan bahwa hingga 12 oktober 2013, sudah 37.905 buruh yang menjadi korban PHK akibat industri yang bangkrut karena krisis ekonomi global tersebut. Sebagai negara dengan jumlah penduduk Muslim terbesar di dunia, dapat ditebak bahwa sebahagian besar dari orang-orang miskin tersebut adalah Muslim. Untuk itu perlu dipikirkan jalan keluar bagi mereka yang berada dalam kesulitan ekonomi. Untuk pengentasan kemiskinan, aktifitas dakwah yang efektif sungguh sangat diperlukan dalam menggugah kesadaran masyarakat Muslim untuk membantu saudara-saudaranya. Bagi penulis, cara-cara filosofis dan reformis masih sangat diperlukan dalam pengentasan kemiskinan ummat Islam di Indonesia. Para pelaksana dakwah harus mampu menggugah kesadaran para Muslim yang memiliki potensi finansial, ketrampilan, waktu dan tenaga untuk membantu saudara-saudaranya yang sedang mengalami kesulitan ekonomi. Berikut kita memperbaruhi lembaga-lembaga sosial dan keagamaan juga harus dilakukan dengan sungguh-sungguh. Agar problema kemiskinan bisa terkurangi pada masa sekarang dan akan datang

Steroidi i poliketidi iz kore biljke Uvaria hamiltonii

Two known steroids, stigmasterol and 6beta-hydroxystigmasta-4,22-dien-3-one (1) and two unusual polyketides, cis-4-hydroxymellein (2) and trans-4-hydroxymellein (3) were isolated from the stem bark of Uvaria hamiltonii. The structures of the compounds were elucidated independently by high-resolution 2D-NMR techniques and confirmed by comparison with previously reported values.Dva poznata steroida, stigmasterol i 6-hidroksistigmasta-4,22-dien-3-on (1) i dva neuobičajena poliketida, cis-4-hidroksimelein (2) i trans-4-hidroksimelein (3) izolirana su iz kore biljke Uvaria hamiltonii. Strukture spojeva određene su neovisno 2D-NMR spektroskopijom visoke rezolucije i usporedbom s literaturnim podacima

Optical imaging of finger for blood pressure monitoring of the driver

Cardiovascular diseases (CVDs) are number one reason for human mortality around the world (Fig. 1) [1]. Pulse pressure (PP) and pulse rate (PR) are considered as the two most vital physiological markers for CVDs like myocardial infarction, cardiac arrhythmia, and heart failure. Currently, long-term PP and PR analysis is not possible due to the lack of systems that can frequently measure the data over a period of time. Motor vehicle drivers with known CVDs are at higher risk due to traffic air pollution. This paper presents our work on an inexpensive and readily deployable approach that keeps track of PP and PR with simple cameras. The computation of PP and PR makes the real-time monitoring possible. The approach makes it highly customizable and ready for on-the-go use in field by drivers, construction zone workers, healthcare workers, law enforcement agencies, etc. The video recordings of fingertips were made using a cellphone camera. The analysis extracted the pulse pressure, which was the difference between systolic and diastolic pressures, and pulse rate. The PP measured with this system was compared with a standard off-the-shelf tool. The comparison showed high accuracy. The measurement of PRs also showed a high level of reliability in comparison to the standard tool. The fundamental concept of the technology depended on the measurement of blood quantity in the fingertip arteries. The amount of blood on fingertips was different during systolic and diastolic phases. This created light intensity variations, which were extracted by analyzing the video frames. A simple embodiment of this approach can be in the dashboard of cars with a camera to create short high-resolution videos of fingertips. The doctors can remotely monitor their patients through a standard computer interface. The patients can also be trained to interpret the results of the measurement

Comparison between kNN and SVM for EMG Signal Classification

This paper shows an approach for EMG signal processing and classification as a tool to classify neuromuscular disorder. EMG signal classification is an emerging field of science and engineering providing efficient way for diagnosing neuromuscular disorder. Several techniques have been suggested for classification of EMG signals.This paper shows an approach for EMG signal processing and classification based on discrete wavelet transform as a tool to extract important information such as approximate and detail coefficients. Present work shows the comparison of kNN (k-Nearest Neighbours) and Support vector machin

Judicial enforceability of economic, social and cultural rights in Bangladesh : a critical evaluation

The implementation of economic, social and cultural rights (esc rights) continues to pose uncertainties in the modern world. Given that many states constitutionally treat such rights as aspirational and not justiciable, it is difficult to enforce them judicially at the domestic level. Bangladesh has embodied these rights in Part ii of its Constitution as a social welfare goal of the State. This article takes Bangladesh as a case study and examines the international legal framework for the implementation of esc rights at the domestic level. Making a comparison with other jurisdictions, such as India and South Africa, the article examines the approach of the judiciary of Bangladesh (the Supreme Court) in giving effect to these rights. Lastly, the article argues that the court should devise appropriate and effective enforcement mechanisms for these rights

Wireless Sensor Node Employed Air Quality Monitoring and Analysis based on Gsm

The main objective of this project is to devise a simple low cost microcontroller based air pollution monitoring system using wireless technology which finds presence of various gases like CO2, SO, NO,etc and parameters like humidity ,temperature ,etc. , displays it on LCD and forwards it to remote user. This project is developed by using PIC 16F877A Microcontroller, SIM 900 GSM Module, JHD204A LCD display and gas sensors. The advantage of using GSM based technology is that GSM based communication network is distributed over a large area and have almost reached to every part of this 21st century world. GSM technology also do provide users with high quality signal and channels, giving them access to high quality digital communication at reasonable cost. This embedded system can prove to be useful for anyone who wish to monitor the quality of air at a location without being physically present there .The main advantages of the research are that the system may be able to collect the pollution levels throughout the 24 hours of the day and that the data so collected may serve as a data base which can be used for various analysis whenever required .The system may offer pollutant levels of a particular industry and this estimation may serve as an enchiridion to the government for allowing or disallowing a particular industry to be set up in a particular area